446 



APPENDIX 



referred to, which reached the Florida keys from the St. Paul's 

 Rocks area, travelling at a rate of not less than 18*4 miles a day. 



Note 2 (p. 10). 

 The local beach-drift of the Turks Islands, 



The beach-drift derived from strand plants growing on the Turks 

 Islands is often disguised by the mass of the foreign drift. But in 

 the islands where there are mangrove swamps, as on Grand Turk, 

 the germinating fruits and seedlings of the trees composing them, 

 Rhizophora mangle, Avicennia nitida, and Laguncularia racemosa, 

 are not infrequently thrown up on the beaches on the weather coasts. 

 Although it is safest to assume that most of thern are of local origin, 

 some of the seedlings of Rhizophora mangle that I observed had all 

 the appearance of having been long afloat ; and it is likely that they 

 came with the foreign drift. Several of the stranded Rhizophora 

 seedlings, which had been more or less covered over with the Sargasso 

 weed that is heaped up in quantities on these beaches, had established 

 themselves firmly in the sand by rootlets three or four inches long. 



The larger local drift other than that derived from the mangroves 

 is represented by the fruits of Coccoloba uvifera. However, much 

 of the local beach-drift is made up of the small seeds and seed vessels 

 of plants growing in the vicinity, such as Ipomcea pes-capro3, Sccevola 

 plumieri, Suriana maritima, Tournefortia gnaphalodes, etc. This 

 fine drift is sometimes sifted out by the waves and deposited higher 

 up the beach away from the heavier large foreign drift, where it is 

 generally associated with small rounded pumice pebbles 5 to 12 mm. 

 across. 



Note 3 (p. 278). 



The effects of wind-pressure on some of the shrubs of the more 

 exposed cays of the Turks Islands. 



These effects are well exhibited in the two small wind-swept 

 islands of Pear Cay and Eastern Cay on the weather or eastern 

 borders of the group. The trade winds seem to blow home with 

 greater force on the weather cays, and it is here that the frequent 

 gales and the occasional hurricanes seem to expend much of their 

 repressive influence on the vegetation. The adaptive habit of growth 

 is strikingly shown in the cases of Corchorus hirsutus, Suriana mari- 

 tima, and Tournefortia gnaphalodes. They all at first bend prone 

 with the wind, the trunks and prostrate branches rooting in the sand, 

 held down firmly by rootlets several inches long, the subsequent 

 behaviour varying in the different plants. 



In the case of Corchorus hirsutus the plant was prostrate along its 

 entire length, its leafy branches spreading out like a fan on the sand 

 and rooting freely and firmly, the whole measuring from ten to fifteen 

 feet instead of three or four feet, the usual height of the erect indi- 

 vidual. In such wind-swept stations it made no effort to assume the 

 upright position. On the other hand, with the shrubs of Tournefortia 

 and Suriana the erect habit ultimately asserted itself, the leafy 



